It is known in the prior art to provide vehicle seats which can be horizontally adjusted to a plurality of positions and which can also be displaced forwardly to an easy enter position upon tilting movement of a vehicle seat back. Such seats are supported for movement by track mechanisms and are of two general types. In one type, tilting movement of the seat back moves the seat to the easy enter position and return of the seat back to upright position moves the seat to its rearwardmost position. Thereafter the seat must be readjusted to the desired horizontal position. In the other type, the return of the seat back to the upright position returns the seat to the initial starting position.
The seat control mechanism of this invention is of the latter type but differs from prior art mechanisms in that, in its preferred embodiment, it includes a pawl which is movable relative to two elongate detent members in order to obtain movement of the seat to the various desired positions. One detent member is mounted to one track member and includes a number of longitudinally spaced recesses. The other detent member is mounted to the other track member and includes only a single recess. The pawl is supported for rotative movement relative to the recesses of the detent members by a support which is slidably mounted on a guide mounted to the other track member. The rotative movement of the pawl is controlled by a control rod mounted to the other track member and slidably and non-rotatably connected to the pawl. The control rod is rotated either by a manual operator or by a connection to the tilting seat back. The pawl and control rod are resiliently biased to normally locate the pawl in engagement with one of the spaced recesses and the single recess to lock the track members to each other.
In order to adjust the seat to a desired horizontal position, the manual operator is actuated to rotate the control rod. This unlocks the track members as the pawl rotates out of engagement with the one spaced recess while remaining in engagement with the single recess. After movement of the seat to the desired position, the actuator is released and the pawl is returned into engagement with the one spaced recess indicative of the desired position to lock the track members to each other. To move the seat to the easy enter position, the seat back is tilted forwardly from the normal upright position to rotate the control rod and move the pawl out of the single recess while remaining in engagement with the one spaced recess. This unlocks the track members for forward displacement of the seat and other track member to the easy enter position. The guide and control rod move with the other track member relative to the pawl support, the pawl, and the one track member. Upon return of the seat back to the upright position, the seat can be displaced rearwardly toward its initial starting position. During this movement, the pawl rides along the other detent member until it comes into engagement with the single recess thereof to again lock the track members to each other in the initial starting position of the seat. Once the seat has started to move toward the easy enter position, the seat back can be returned to its upright position since the pawl will ride along the other detent member. The manual operator can also be actuated to rotate the control rod and move the pawl out of the single recess in order to obtain forward displacement of the seat to the easy enter position. Again, once the seat has started to move toward the easy enter position the manual operator can be released.
If desired, the track members may be curved so as to provide for upward movement of the seat upon forward displacement thereof. The guide and detent members can be correspondingly curved to ensure that the pawl always has the same relationship to the detent members. The control rod for the pawl carries no loads and therefore can be flexible so as to flex as the pawl support and pawl move relative to the control rod upon forward displacement of the seat to the easy enter position and return of the seat to the initial starting position.
The primary feature of this invention is that it provides an improved seat position control mechanism for a horizontally displaceable vehicle seat which permits the seat to be adjusted to a number of horizontal positions and also permits the seat to be displaced forwardly to an easy enter position and returned to its initial starting position. Another feature is that it provides such a mechanism having seat track members which are locked to each other by a movable pawl engageable in pawl receiving recesses provided in detent members on each of the track members. A further feature is that one of the detent members includes a number of spaced recesses and the other detent member includes only a single recess, with the pawl being receivable in one of the spaced recesses and the single recess to lock the track members and set the horizontal position of the seat. Yet another feature is that the pawl is rotatable out of engagement with the one spaced recess while remaining in engagement with the single recess to unlock the track members and permit horizontal adjustment of the seat. Yet a further feature is that the pawl is rotatable out of engagement with the single recess while remaining in engagement with the one spaced recess to unlock the track members and permit the seat to be displaced from an initial starting position to an easy enter position, with return of the seat to the initial starting position permitting the pawl to again reengage the single recess to reestablish the seat in the initial starting position. Still another feature is that the pawl can be moved to its various positions either through a control rod which is manually actuated or by tilting movement of the seat back.